Tuesday, May 1, 2007

Joy's New and Hot, Week 5

Was the earth's atmosphere enough to create primordial soup?

My article comes from Scientific American and discusses the possibility that early earth's atmosphere could have had the necessary ingredients for life, versus the idea that these essentials came from the outside forces of comets and meteors. This idea is brought up by the recreation of a famous experiment first done by Stanley Miller at the University of Chicago in 1953. Miller used a sparking device to mimic the lightning storms of early earth with a mixture of methane and ammonia. This experiment produced a brown liquid rich in amino acids. The experiment was groundbreaking, until it was established that earth's atmosphere probably didn't contain the gases Miller used, but rather a mix of carbon dioxide and nitrogen. When Miller retried the experiment in 1983 with these gases, a colorless liquid containing only a few amino acids. Creationists picked this up as proof that life can't be created in a lab.

However, Jeffrey Bada, a chemist at Scripps Oceanographic Institute, who was mentored by Miller, has discovered something adding new insight into the experiment. He discovered that the reactions were producing nitrites, compounds which quickly destroy amino acids. However, earth's atmosphere would have contained iron and carbonate minerals which neutralize these nitrites. When he reran the experiment with these included, he produced the same colorless liquid, but now it was full of amino acids.

However, while this lends insight into what conditions might really have been like on ancient earth, scientists still debate whether earth's atmosphere alone could have created the building blocks of life.